Power supply system



July 19, 1938. H. o. ROOSENSTEIN 2,123,968

POWER SUPPLY SYSTEM Filed Oct. 12, 1935 INVENTOR. HANS OTTO ROOSENSTEIN ATTORNEY.

Patented July 19, 1938 PATET FFEQE POWER SUPPLY SYSTEM Hans Otto Roosenstein, Berlin, Germany, as-

signor to Telefunken Gesellschaft fiir Drahtlose Telegraphic m. b. H., poration of Germany Application October 12 Berlin, Germany, a cor- 1935, Serial No. 44,696

In Germany August 26, 1934 3 Claims.

The present invention relates to the arrangement of transformers and the like in equipment comprising cathode ray tubes, and more particularly television apparatus.

In the operation of cathode ray tubes, for the purpose of causing acceleration of the electrons, voltages of several thousand volts are required which, for reasons of economy, are mostly derived from transformers. Whenever it is desired that the dimensions of the cathode ray tube and the transformer in the equipment should not be unduly large so that arrangements of compact construction are obtained, an action by the ap- Dreciable field set up around the transformer upon the easily defiectable cathode ray pencil will be unavoidable. The said action manifests itself, for instance, by distortions of the picture thrown upon the screen.

It has been suggested in the prior art to enclose the transformer inside a casing designed to shield the field of the transformer. However, schemes of this kind are incapable of completely precluding the actions of the field upon the electrons of the pencil inasmuch as the shielding is not perfect.

Now, the invention discloses ways and means with a view to minimizing or obviating actions on the electron pencil by a special disposition of the transformer. The invention shall be explained in more detail in what follows by reference to the drawing in which Fig. 1 shows in end view, one embodiment of my invention in which the power transformer is positioned parallel to the axis of the cathode ray tube, and Fig. 2 shows an elevation view of the embodiment of my invention, together with suggested magnetic lines of force in relation to the cathode ray tube.

Referring to Fig. l of the drawing, K is a cathode ray tube whose axis must be imagined to be at right angles to the plane of the drawing. HH is the horizontal and VV the vertical direction of the spot upon the screen. T is a transformer comprising a winding W and a yoke consisting of ferro-magnetic material J. In order that the horizontal component of the undesirable or stray deflection of the cathode ray pencil due to action of the transformer field may be made equal to zero, the axis of the cathode ray tube, according to this invention, is first brought into 50 the plane of symmetry S-S of the transformer T. In an arrangement according to Fig. l, as will thus be seen, there would be possible or imaginable only a vertical deflection of the pencil. In order that this chance may also be precluded the transformer is so shifted symmetrically in reference to the plane SS that also the vertical components of the field become neutralized.

For explanation of the idea reference may be made to Fig. 2. If the transformer occupies the position marked I, then the lines of force of the field will be positioned approximately in a way as indicated by the dotted line 7. Between points B and C, inasmuch as the lines of force are practically positioned parallel to the cathode ray pencil, no deflection is able to occur. However, at the curved portions of the said lines of force action upon the cathode ray pencil is possible in the perpendicular sense V--V, in fact, the sense of action on the left-hand side of the horizontal part of the force-lines BC is contrary to the direction of action on the right of the horizontal part BC. If the cathode ray pencil along its trajectory or path had throughout the same rate of velocity, then, in position I of the transformer, the oppositely directed actions of the field upon the pencil would be neutralized. However, as a general rule, the pencil initially has a low and later an increased rate of speed so that action results upon both sides of BC-and disturbance tothe ray pencil. By shifting and turning .the transformer symmetrically to the plane SS as shown in Fig. 1, however, it will always be possible to make conditions so that the opposite vertical actions upon both sides of line BC, even in the presence of different pencil velocities will be practically completely eliminated along the pencil trajectory. It has been proved to be of practical advantage if the leg of the transformer turned away from the cathode ray tube should be wound in a way as illustrated in the drawing.

Having now described the invention, what I claim is:

1. The method of avoiding distortion in the deflection of a cathode ray beam by the magnetic field of a power supply transformer, which comprises the steps of developing a cathode ray beam and projecting the beam along a predetermined path, deflecting the developed beam at one point in said path in one direction by a portion of the magnetic field of the transformer, deflecting the developed beam at a different point in said path in an opposite direction by a different portion of the magnetic field, and adjusting the position of the transformer to make the effective deflection of the beam at a predetermined plane equal to zero.

2. A power supply system for distortionless defiection operation of cathode ray apparatus, comprising a cathode ray tube wherein an electron beam is developed and projected along a predethe transformer tending to increase and decrease the beam velocity, is equal to zero.

3. The combination of a cathode ray tube wherein a developed beam of electrons is projected along a predetermined path, and a power transformer, from which stray magnetic fields are present, positioned to deflect thebeam of electrons at two diiferent points in said path effectively equally in opposite directions by two different portions of said fields.

HANS OTTO ROOSENSTEIN. 

